EP0244204A1 - Low pressure atomization nozzle - Google Patents
Low pressure atomization nozzle Download PDFInfo
- Publication number
- EP0244204A1 EP0244204A1 EP19870303754 EP87303754A EP0244204A1 EP 0244204 A1 EP0244204 A1 EP 0244204A1 EP 19870303754 EP19870303754 EP 19870303754 EP 87303754 A EP87303754 A EP 87303754A EP 0244204 A1 EP0244204 A1 EP 0244204A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- substance
- gas
- orifice
- liquid
- nozzle assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/0081—Apparatus supplied with low pressure gas, e.g. "hvlp"-guns; air supplied by a fan
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/02—Spray pistols; Apparatus for discharge
- B05B7/04—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge
- B05B7/0416—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid
- B05B7/0441—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber
- B05B7/0458—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber the gas and liquid flows being perpendicular just upstream the mixing chamber
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/02—Spray pistols; Apparatus for discharge
- B05B7/04—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge
- B05B7/0416—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid
- B05B7/0441—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber
- B05B7/0475—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber with means for deflecting the peripheral gas flow towards the central liquid flow
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/02—Spray pistols; Apparatus for discharge
- B05B7/06—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane
- B05B7/062—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet
- B05B7/066—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet with an inner liquid outlet surrounded by at least one annular gas outlet
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/02—Spray pistols; Apparatus for discharge
- B05B7/10—Spray pistols; Apparatus for discharge producing a swirling discharge
Definitions
- This invention relates to a nozzle assembly which utilizes a first substance to accelerate a second substance and, more particularly, to a nozzle assembly which utilizes a gas for accelerating an adhesive which is then propelled from the nozzle assembly.
- Nozzles are used to propel or spray liquids and are generally classified into “liquid only” nozzles, which use high liquid pressure to propel, spray or atomize the fluid, and “liquid-gas” nozzles which utilize a pressurized gas, such as compressed air, in association with the liquid stream, the gas being used to accelerate and propel the fluid.
- a pressurized gas such as compressed air
- valve mechanisms of this type have by necessity been equipped with a valve mechanism to intermittently terminate liquid flow.
- a minute liquid residue is retained on the valve mechanism after it is closed. This residue can build up over a period of time and clog the orifice of the valve and/or adversely affect its opening and closing operation particularly when the liquid being sprayed is an adhesive. This is disadvantageous.
- a further disadvantage of known liquid-gas nozzles is that they use relatively large gas flows to achieve satisfactory atomization of the liquid. Downstream turbulence associated with these large gas flows carries fine particles into the atmosphere and causes "overspray". Overspray contaminates the atmosphere in the vicinity of the nozzle and requires costly cleanup and equipment maintenance.
- a nozzle assembly comprising first inlet means, second inlet means, and an exit means, said first inlet means being positioned to supply a first substance in an inwardly direction towards said second inlet means, said second inlet means being operable to supply a second substance in a direction substantially normal to said inwardly direction of said first substance, and said exit means being positioned downstream of said first and second inlet means and being operable to simultaneously eject both said first and second substances.
- a nozzle assembly comprising gas inlet means positioned to supply gas inwardly towards the periphery of a liquid inlet orifice, an exit orifice located downstream from said gas inlet means and said liquid inlet orifice, said exit orifice being operable to simultaneously discharge both said gas from said gas inlet means and said liquid from said liquid inlet orifice.
- a method of discharging a first and second substance from a nozzle assembly comprising the steps of supplying said first substance in an inwardly direction towards an inlet orifice for said second substance, supplying said second substance in a direction substantially normal to the inwardly direction of said first substance and simultaneously discharging said first and second substances from an exit orifice located downstream from said inlet orifice for said second substance.
- a method of discharging gas and liquid comprising supplying gas in an inwardly direction towards a liquid orifice, discharging liquid from said liquid orifice while supplying said inwardly directed gas and simultaneously discharging said liquid and gas through an exit orifice located downstream of said liquid orifice and said supply of gas.
- FIG. 1 a nozzle assembly according to the invention is generally shown at 100.
- Such an assembly 100 is used in adhesive application processes where a first substance introduced is gas and a second substance introduced is adhesive.
- the nozzle assembly 100 comprises an adhesive inlet or supply orifice generally shown at 101, an air inlet passage generally shown at 102 and an exit orifice 103 formed as a circumference extending through exit plate 104.
- the adhesive supply orifice 101 comprises an accumulation area 110 to store and hold the adhesive as may be more clearly seen in Figure 7 and a circumferential exit area 111 from which the adhesive is emitted.
- Control of adhesive flow is by a tapered needle valve assembly 125 positioned inside the supply orifice 101, which moves in a linear direction as indicated under the influence of a pneumatic cylinder 126 and piston 127 as seen in Figure 7.
- the needle valve 125 intermittently blocks the discharge orifice or exit area 111 when adhesive flow is not required.
- the air inlet passage 102 ( Figure 1) acts to provide generally inwardly directed air streams which converge at the axis 105 of the supply orifice 101.
- the discharge or exit area 111 of adhesive inlet orifice 101 is upstream of exit orifice 103 in exit plate 104.
- the nozzle assembly 113 comprises a circumferential exit orifice 114 extending through the exit plate 120, an adhesive inlet orifice 121 located upstream of the exit orifice 114 and a series of air inlet passages 124 ( Figure 3) which supply air in a direction having velocity components both normal and tangential to a radius extending from the axis 123 of the adhesive inlet orifice 121.
- the proportion of normal and tangential velocity components in the air flow can be modified by controlling the offset distance as illustrated in Figure 3.
- the nozzle assembly 113 ( Figure 2) will be used primarily to produce a spray pattern wherein "overspray” as defined in the BACKGROUND area of the specification is minimized and a precise application of the adhesive exiting from the nozzle assembly 100 is achieved.
- One factor which determines the width of the spray pattern is the offset distance ( Figure 3) of the air inlet passages 124 to achieve the correct proportion of tangential and normal airflow components in the nozzle assembly 100. The air, therefore, spins as it flows inwardly in passages 124 and surrounds the adhesive inlet orifice 121 ( Figure 2) and turns upwardly towards the exit orifice 114 in a direction substantially normal to its inwards flow.
- the needle valve assembly 125 is intermittently opened as desired by the action of the pneumatic cylinder 126 and adhesive is discharged from the adhesive discharge orifice 111 as a flow which is accelerated by the rapidly moving air whereupon the air and adhesive pass through the exit orifice 114 ( Figure 4) in the form of a filament 132.
- the filament 132 oscillates or "waves" after leaving the exit orifice 114 and it becomes progressively thinner the further it moves from the exit orifice 114. Surface tension effects then cause the filament 132 to break up into discrete particles or droplets 133 at some distance from the exit orifice 114.
- a factor that determines where the discharged adhesive emitted by nozzle assembly 113 changes to droplets is the viscosity and surface tension of the particular adhesive or substance being emitted from the adhesive inlet orifice 121. If, for example, the substance is of a relatively low viscosity, it will break up into droplets 133 only a relatively short distance from the exit orifice 114 of the nozzle assembly 113. If the substance is of a relatively high viscosity, such as adhesive, the substance will break into droplets a relatively greater distance from the exit orifice 114 as illustrated generally in Figure 4 although Figure 4 also contemplates a radial air supply as shown in Figure 5.
- a deposit pattern comprising either filaments or discrete droplets may be obtained as desired.
- the adhesive 130 being supplied from adhesive inlet orifice 121 is impinged upon on its periphery by the inwardly directed air stream 131.
- the impingement and the subsequent ninety (90) degree or normal direction change made by the air around the adhesive causes the adhesive 130 to be formed into a filament 132 which, as it leaves the exit orifice 114, moves with an ever increasing amplitude of oscillation until it eventually breaks into droplets 133.
- a further factor used to modify the "break up" distance from the exit orifice 114 of the filaments into droplets is by providing an increasing or decreasing supply of air. If the air supply through the air nozzles 124 is increased, for example, the filaments 132 ( Figure 4) will be deflected into a wider pattern and the filament breakup distance from the exit orifice 114 and exit plate 104 will be decreased. At some point of increased air supply and at some value for offset distance ( Figure 3), the nozzle assembly 100 will reach its most efficient spray pattern which, of course, can vary depending on the substances used and the target pattern required.
- the frequency of the spin should be approximately equal to the actual frequency of the nozzle, the frequency being obtained experimentally and, as well, approximately theoretically by the following equation;
- m air mass flow rate;
- N ratio of adhesive velocity to air velocity;
- p density of air;
- d exit plate orifice diameter;
- s width of air slot (linear dimension see Figure 6) which is equal to d for assumption purposes;
- g a numerical factor in the order of unity which represents the friction coefficient of the orifice.
- FIG. 6 illustrates a further embodiment of the invention.
- air flows in a linear direction along a rectangular air pipe 136 and converges from both ends around the adhesive supply orifice 115.
- the adhesive supply orifice 115 is upstream of the final exit orifice 137 and the air impinges upon the emitted adhesive and turns 90° as it is directed towards and subsequently emitted from the exit orifice 137.
- abrasive particles are emitted by the "adhesive" or low pressure orifice 121 and they are controlled by the inwardly directed air stream to an extent where the abrasive material passes through the discharge or exit orifice 114 through the exit plate 104 without substantial contact.
- the nozzle life therefore, is increased because of the reduced wear generally attributed to abrasive discharge nozzles caused by grit scouring the exit nozzle orifice. Water, rather than air, could, of course, be used as the high pressure propellant.
- Yet another application contemplates the nozzle assembly in aerosol containers.
- the improved efficiency of the nozzle makes it possible to operate at lower gas pressures, offering significant advantages of safety and lower costs.
- the pressures required for the individual substances which are supplied to the nozzle are also of interest. For example, it is maybe advantageous to supply one of the two substances to the nozzle under a relatively high pressure and the other of the substances under relatively low pressure. Such a pressure differential has the potential to modify the exit characteristics of the nozzle, particularly in relation to specific substances used in the nozzle.
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- Nozzles (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
Abstract
A low pressure atomizing nozzle with separate inlet orifices for a first and second substance. The first substance is supplied inwardly towards the supply orifice of the second substance and changes in direction substantially ninety (90) degrees wherein the first and second substances flow simultaneously outwardly of an exit orifice located downstream of both inlet orifices. Provision is made for supplying the first substance with a tangential velocity component around the supply orifice of the second substance. The second substance flows from its supply orifice with a velocity component normal to the inwardly direction taken by the first substance as it flows towards the supply orifice of the second substance.
Description
- This invention relates to a nozzle assembly which utilizes a first substance to accelerate a second substance and, more particularly, to a nozzle assembly which utilizes a gas for accelerating an adhesive which is then propelled from the nozzle assembly.
- Nozzles are used to propel or spray liquids and are generally classified into "liquid only" nozzles, which use high liquid pressure to propel, spray or atomize the fluid, and "liquid-gas" nozzles which utilize a pressurized gas, such as compressed air, in association with the liquid stream, the gas being used to accelerate and propel the fluid.
- Previous nozzles of the liquid-gas variety have by necessity been equipped with a valve mechanism to intermittently terminate liquid flow. In valve mechanisms of this type, a minute liquid residue is retained on the valve mechanism after it is closed. This residue can build up over a period of time and clog the orifice of the valve and/or adversely affect its opening and closing operation particularly when the liquid being sprayed is an adhesive. This is disadvantageous.
- A further disadvantage of known liquid-gas nozzles is that they use relatively large gas flows to achieve satisfactory atomization of the liquid. Downstream turbulence associated with these large gas flows carries fine particles into the atmosphere and causes "overspray". Overspray contaminates the atmosphere in the vicinity of the nozzle and requires costly cleanup and equipment maintenance.
- Yet a further disadvantage of present nozzles in situations requiring intermittent operation is that the application of the liquid being propelled from such nozzles to a target is relatively imprecise due to the inconsistent atomization of the liquid being propelled. When applying adhesive, for example, in certain packaging related operations, it is necessary to lay down a precise, intermittent adhesive pattern in order to prevent the adhesive from contaminating adjacent surfaces. It is desirable, however, to apply adhesive over as wide a surface area as possible in order for its function to be well served. To achieve both objectives simultaneously is difficult.
- Yet a further disadvantage with existing nozzles is that the atomizing pressures required are high. Using high pressures are costly because of the greater volumes of air which are required.
- Yet a further disadvantage with present nozzles is the difficulty inherent in atomizing higher viscosity fluids such as cold set PVA adhesives which may have a viscosity in the order of 1500 centipoises or greater.
- Yet a further disadvantage with existing nozzles is more specific to abrasive cutting where ceramic nozzles are used for a certain period of time and are then discarded because of the severe wear problems created by the impact of the particle stream with the nozzle orifice when exiting from the nozzle.
- Yet a further disadvantage with present nozzles and, in particular, those nozzles used in aerosol cans is that relatively high gas pressures are required to achieve atomization. This restricts the available choice of propellants for these applications to substances which have high vapour pressures, such as fluoro-chloro-hydrocarbons (e.g., FREONS, etc.). Such propellants are costly and have at least questionable environmental properties.
- According to one aspect of the invention, there is disclosed a nozzle assembly comprising first inlet means, second inlet means, and an exit means, said first inlet means being positioned to supply a first substance in an inwardly direction towards said second inlet means, said second inlet means being operable to supply a second substance in a direction substantially normal to said inwardly direction of said first substance, and said exit means being positioned downstream of said first and second inlet means and being operable to simultaneously eject both said first and second substances.
- According to a further aspect of the invention, there is disclosed a nozzle assembly comprising gas inlet means positioned to supply gas inwardly towards the periphery of a liquid inlet orifice, an exit orifice located downstream from said gas inlet means and said liquid inlet orifice, said exit orifice being operable to simultaneously discharge both said gas from said gas inlet means and said liquid from said liquid inlet orifice.
- According to yet a further aspect of the invention, there is disclosed a method of discharging a first and second substance from a nozzle assembly comprising the steps of supplying said first substance in an inwardly direction towards an inlet orifice for said second substance, supplying said second substance in a direction substantially normal to the inwardly direction of said first substance and simultaneously discharging said first and second substances from an exit orifice located downstream from said inlet orifice for said second substance.
- According to yet a further aspect of the invention, there is disclosed a method of discharging gas and liquid comprising supplying gas in an inwardly direction towards a liquid orifice, discharging liquid from said liquid orifice while supplying said inwardly directed gas and simultaneously discharging said liquid and gas through an exit orifice located downstream of said liquid orifice and said supply of gas.
- A specific embodiment of the invention will now be described, by way of example only, with the use of drawings in which:
- Figure 1 is a general sectional diagramatic view of the nozzle assembly according to the invention;
- Figure 2 is a sectional view of a second embodiment of the nozzle assembly according to the invention;
- Figure 3 is a partial sectional diagramatic plan view of the nozzle assembly taken along the line III-III of Figure 2;
- Figure 4 is a diagramatic illustration of the nozzle assembly under operating conditions;
- Figure 5 is a diagramatic view taken along V of Figure 4;
- Figure 6 is a plan view of a third embodiment of the nozzle assembly according to the invention; and
- Figure 7 is a diagrammatic sectional view of a supply orifice in the nozzle assembly according to the invention illustrating particularly the needle valve assembly.
- Reference is initially made to Figure 1 in which a nozzle assembly according to the invention is generally shown at 100.
- Such an
assembly 100 is used in adhesive application processes where a first substance introduced is gas and a second substance introduced is adhesive. - The
nozzle assembly 100 comprises an adhesive inlet or supply orifice generally shown at 101, an air inlet passage generally shown at 102 and anexit orifice 103 formed as a circumference extending throughexit plate 104. Theadhesive supply orifice 101 comprises anaccumulation area 110 to store and hold the adhesive as may be more clearly seen in Figure 7 and a circumferential exit area 111 from which the adhesive is emitted. Control of adhesive flow is by a taperedneedle valve assembly 125 positioned inside thesupply orifice 101, which moves in a linear direction as indicated under the influence of apneumatic cylinder 126 andpiston 127 as seen in Figure 7. Theneedle valve 125 intermittently blocks the discharge orifice or exit area 111 when adhesive flow is not required. - The air inlet passage 102 (Figure 1) acts to provide generally inwardly directed air streams which converge at the
axis 105 of thesupply orifice 101. The discharge or exit area 111 ofadhesive inlet orifice 101 is upstream ofexit orifice 103 inexit plate 104. - Reference is now made to Figures 2 and 3 which illustrate a second embodiment of a nozzle assembly generally shown at 113. In this embodiment, the
nozzle assembly 113 comprises acircumferential exit orifice 114 extending through theexit plate 120, anadhesive inlet orifice 121 located upstream of theexit orifice 114 and a series of air inlet passages 124 (Figure 3) which supply air in a direction having velocity components both normal and tangential to a radius extending from theaxis 123 of theadhesive inlet orifice 121. The proportion of normal and tangential velocity components in the air flow can be modified by controlling the offset distance as illustrated in Figure 3. - While the explanations given hereafter which relate to the operation of the nozzle assembly are believed to be correct and are the best knowledge currently possessed by the applicant, it is emphasized that subsequent investigations may modify or even disprove the explanations given hereafter. Applicant, therefore, would not wish to be bound by the explanations given if such improved information subsequently comes to hand.
- It will be first anticipated that the nozzle assembly 113 (Figure 2) will be used primarily to produce a spray pattern wherein "overspray" as defined in the BACKGROUND area of the specification is minimized and a precise application of the adhesive exiting from the
nozzle assembly 100 is achieved. One factor which determines the width of the spray pattern is the offset distance (Figure 3) of theair inlet passages 124 to achieve the correct proportion of tangential and normal airflow components in thenozzle assembly 100. The air, therefore, spins as it flows inwardly inpassages 124 and surrounds the adhesive inlet orifice 121 (Figure 2) and turns upwardly towards theexit orifice 114 in a direction substantially normal to its inwards flow. Theneedle valve assembly 125 is intermittently opened as desired by the action of thepneumatic cylinder 126 and adhesive is discharged from the adhesive discharge orifice 111 as a flow which is accelerated by the rapidly moving air whereupon the air and adhesive pass through the exit orifice 114 (Figure 4) in the form of afilament 132. Thefilament 132 oscillates or "waves" after leaving theexit orifice 114 and it becomes progressively thinner the further it moves from theexit orifice 114. Surface tension effects then cause thefilament 132 to break up into discrete particles ordroplets 133 at some distance from theexit orifice 114. - In this embodiment, where spinning air is introduced, a factor that determines where the discharged adhesive emitted by
nozzle assembly 113 changes to droplets is the viscosity and surface tension of the particular adhesive or substance being emitted from theadhesive inlet orifice 121. If, for example, the substance is of a relatively low viscosity, it will break up intodroplets 133 only a relatively short distance from theexit orifice 114 of thenozzle assembly 113. If the substance is of a relatively high viscosity, such as adhesive, the substance will break into droplets a relatively greater distance from theexit orifice 114 as illustrated generally in Figure 4 although Figure 4 also contemplates a radial air supply as shown in Figure 5. By placing the target at an appropriate distance from thenozzle assembly 113 andexit orifice 114, a deposit pattern comprising either filaments or discrete droplets may be obtained as desired. - With reference again to Figure 4 and to summarize the general nozzle operation, the adhesive 130 being supplied from
adhesive inlet orifice 121 is impinged upon on its periphery by the inwardly directedair stream 131. The impingement and the subsequent ninety (90) degree or normal direction change made by the air around the adhesive causes theadhesive 130 to be formed into afilament 132 which, as it leaves theexit orifice 114, moves with an ever increasing amplitude of oscillation until it eventually breaks intodroplets 133. - A further factor used to modify the "break up" distance from the
exit orifice 114 of the filaments into droplets is by providing an increasing or decreasing supply of air. If the air supply through theair nozzles 124 is increased, for example, the filaments 132 (Figure 4) will be deflected into a wider pattern and the filament breakup distance from theexit orifice 114 andexit plate 104 will be decreased. At some point of increased air supply and at some value for offset distance (Figure 3), thenozzle assembly 100 will reach its most efficient spray pattern which, of course, can vary depending on the substances used and the target pattern required. - Yet a further factor affecting nozzle efficiency is the Reynold's number of the flow leaving the
exit orifice 114. With fully laminar flow, there is minimal oscillation of thefilament 132 because such flow is not conducive to forming oscillations. When the flow is fully turbulent, very small vortices and oscillations occur near the edge of the flow which dislocations do not, however, significantly affect the main flow itself. Flows in the transition area, however, having Reynold's numbers between those of laminar and turbulent flow may have a few large oscillations or vortices in the flow. In this range, such oscillations or vortices will affect the characteristics of the flow. By providing flow rates emanating from theexit orifice 114 with Reynold's numbers around 10,000, which numbers lie in the aforementioned transition area between fully turbulent and fully laminar flow, the flow characteristics may be optimized. Thus, it is preferable to have nozzle operation within this range. - Various other factors are involved in obtaining the most desirable and efficient flow rates for specific applications. With reference to Figure 4, however, where efficient droplet deposition is desired, the specific parameters proven satisfactory are as follows:
Gas/liquid mass flow ratio of 1 or larger.
Reynold's number in thefinal exit orifice 114 of about 10,000.
Height ofexit plate 104 aboveadhesive supply orifice 121 being about 1/4 of the diameter of theexit orifice 114.
Frequency of filament oscillation should be between 200 Hz and 2,000 Hz with the higher the frequency, the finer the spray. Very high frequencies should be avoided as the spray is too fine and contaminates theexit plate 120.
Insofar as specific factors have been satisfactory for a nozzle when efficient adhesive filament deposition is desired, the factors listed above are also applicable except for the following changes:
Gas/liquid mass flow ratio of about 0.2
A certain amount of spin should be introduced into the air before it converges on theadhesive orifice 121 by providing air throughair inlet passages 124 at a certain offset distance. The frequency of the spin should be approximately equal to the actual frequency of the nozzle, the frequency being obtained experimentally and, as well, approximately theoretically by the following equation;
N = ratio of adhesive velocity to air velocity;
p = density of air;
d = exit plate orifice diameter;
s = width of air slot (linear dimension see Figure 6) which is equal to d for assumption purposes; and
g = a numerical factor in the order of unity which represents the friction coefficient of the orifice. - In tests conducted to date, with the adhesive used being NACAN 1557 (Trade Mark) which has a viscosity of 1500 centipoises, satisfactory results were obtained with an adhesive flow rate of 0.83 grams/second. The target was located one inch from the nozzle and the target was moved relative to the nozzle at a speed of two ft/sec. The amount of air supplied was 9.0 litres/min. at an offset distance (Figure 3) of 0.040ʺ.
- Reference is now made to Figure 6 which illustrates a further embodiment of the invention. In this embodiment air flows in a linear direction along a
rectangular air pipe 136 and converges from both ends around theadhesive supply orifice 115. Theadhesive supply orifice 115 is upstream of thefinal exit orifice 137 and the air impinges upon the emitted adhesive and turns 90° as it is directed towards and subsequently emitted from theexit orifice 137. - Many modifications are contemplated in the specific embodiments of the nozzle assembly used for adhesive applications. For example, in tests conducted using the nozzle assembly in a form generally as described, the application of solid particles in the form of abrasive material to the target, which abrasive material is propelled by using relatively high pressure air, was found to work very well for cutting purposes. Such abrasive particles are emitted by the "adhesive" or
low pressure orifice 121 and they are controlled by the inwardly directed air stream to an extent where the abrasive material passes through the discharge orexit orifice 114 through theexit plate 104 without substantial contact. The nozzle life, therefore, is increased because of the reduced wear generally attributed to abrasive discharge nozzles caused by grit scouring the exit nozzle orifice. Water, rather than air, could, of course, be used as the high pressure propellant. - Yet another application contemplates the nozzle assembly in aerosol containers. In this case, the improved efficiency of the nozzle makes it possible to operate at lower gas pressures, offering significant advantages of safety and lower costs.
- The pressures required for the individual substances which are supplied to the nozzle are also of interest. For example, it is maybe advantageous to supply one of the two substances to the nozzle under a relatively high pressure and the other of the substances under relatively low pressure. Such a pressure differential has the potential to modify the exit characteristics of the nozzle, particularly in relation to specific substances used in the nozzle.
- While specific embodiments and certain modifications of the invention have been described, such embodiments and modifications should be considered as illustrative only and not as limiting the scope of the invention. Many modifications may be contemplated by those skilled in the art which will still fall within the spirit and scope of the invention as defined in accordance with the accompanying claims.
Claims (21)
1. A nozzle assembly comprising first inlet means, second inlet means, and an exit means, said first inlet means being positioned to supply a first substance in an inwardly direction towards said second inlet means, said second inlet means being operable to supply a second substance in a direction substantially normal to said inwardly direction of said first substance, and said exit means being positioned downstream of said first and second inlet means and being operable to simultaneously eject both said first and second substances.
2. A nozzle assembly as in claim 1 wherein said first substance is air and said second substance is adhesive.
3. A nozzle assembly as in claim 1 wherein said second substance includes abrasive particles and said first substance is air.
4. A nozzle assembly as in claim 1 wherein said first substance is directed inwardly substantially around the periphery of said second inlet means.
5. A nozzle assembly as in claim 1 wherein said first substance is supplied in a radially inwardly direction about the periphery of said second inlet means.
6. A nozzle assembly comprising gas inlet means positioned to supply gas inwardly towards the periphery of a liquid inlet orifice, an exit orifice located downsteam from said gas inlet means and said liquid inlet orifice, said exit orifice being operable to simultaneously discharge both said gas from said gas inlet means and said liquid from said liquid inlet orifice.
7. A nozzle assembly as in claim 6 wherein said exit orifice discharges said gas and said liquid in a direction substantially normal to said inwardly direction of said gas supply.
8. A nozzle assembly as in claim 7 wherein said gas inlet means comprises at least one gas inlet orifice directed to provide gas in a direction offset from the axis of said liquid inlet orifice.
9. A nozzle assembly as in claim 7 wherein said liquid is intermittently discharged from said exit orifice.
10. A nozzle assembly as in claim 6 wherein said liquid is adhesive and said gas is air.
11. A method of discharging a first and second substance from a nozzle assembly comprising the steps of supplying said first substance in an inwardly direction towards an inlet orifice for said second substance, supplying said second substance in a direction substantially normal to the inwardly direction of said first substance and simultaneously discharging said first and second substances from an exit orifice located downstream from said inlet orifice for said second substance.
12. The method of claim 11 wherein said first substance is given a velocity component tangential to a radius extending from the axis of said inlet orifice.
13. The method of claim 12 wherein said first substance is air and said second substance is adhesive.
14. A method of discharging gas and liquid comprising supplying gas in an inwardly direction towards a liquid orifice, discharging liquid from said liquid orifice while supplying said inwardly directed gas and simultaneously discharging said liquid and gas through an exit orifice located downstream of said liquid orifice and said supply of gas.
15. The method of claim 8 wherein said gas contacts said liquid prior to discharge from said exit orifice.
16. The method of claim 9 and further comprising supplying gas to said periphery of said liquid orifice with a tangential component of velocity normal to said velocity of said radially inwardly supplied gas.
17. The method of claim 8 wherein said gas is supplied to said periphery of said liquid orifice in a first direction and said gas is discharged from said exit orifice in a second direction substantially normal to said first direction.
18. The method of claim 7 wherein said gas is supplied to said periphery of said liquid orifice in a first direction and said gas is discharged from said exit orifice in a second direction substantially normal to said first direction.
19. A Nozzle assembly as in claim 1 wherein said first inlet means is at relatively high pressure and said second inlet means is at relatively low pressure.
20. The method of claim 11 wherein said first substance is supplied under relatively high pressure and said second substance is supplied under relatively low pressure.
21. The method of claim 14 wherein said gas is supplied under relatively high pressure.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA507797 | 1986-04-28 | ||
CA507797 | 1986-04-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0244204A1 true EP0244204A1 (en) | 1987-11-04 |
Family
ID=4132992
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19870303754 Withdrawn EP0244204A1 (en) | 1986-04-28 | 1987-04-28 | Low pressure atomization nozzle |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0244204A1 (en) |
JP (1) | JPS62269767A (en) |
CN (1) | CN87104313A (en) |
AU (1) | AU7212487A (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GR890100298A (en) * | 1989-05-05 | 1991-10-10 | Vni Pi Aljuminievoi Magnievoi | Device for atomizing a liquid |
WO1991016991A1 (en) * | 1990-05-09 | 1991-11-14 | Resch D R | Precisely adjustable atomizer |
WO1992013643A1 (en) * | 1991-02-05 | 1992-08-20 | Gunter Voss | Device for coating a pressing chamber with a lubricant |
US5232164A (en) * | 1990-05-09 | 1993-08-03 | Resch D R | Precisely adjustable atomizer |
DE4407779A1 (en) * | 1994-03-09 | 1995-09-14 | Total Feuerschutz Gmbh | Spray nozzle for generating spray mists |
EP0914871A3 (en) * | 1997-11-05 | 2000-05-10 | ITW Limited | Spray nozzle |
GB2392119A (en) * | 2002-07-13 | 2004-02-25 | Daryl Ind Ltd | A nozzle for a showerhead |
DE102005037773B3 (en) * | 2005-08-10 | 2007-01-18 | Voss, Gunter M. | Solvent film application process for surface mold involves applying hollow-cone gas flow, applying medium, and applying hollow-cone gas flow at different gas pressure |
FR2926230A1 (en) * | 2008-01-10 | 2009-07-17 | Air Liquide | APPARATUS AND METHOD FOR VARYING THE PROPERTIES OF A MULTIPHASIC JET. |
WO2011014949A1 (en) * | 2009-08-06 | 2011-02-10 | Unifiller Systems Inc. | A nozzle apparatus for dispersing droplets of flowable material |
ES2543037A1 (en) * | 2014-09-17 | 2015-08-13 | Grupo Técnico Rivi, S.L. | Industrial lubrication system distributed by oil mist (Machine-translation by Google Translate, not legally binding) |
CN105214532A (en) * | 2015-10-28 | 2016-01-06 | 贵州电网有限责任公司电力科学研究院 | New-type boiler denitration ammoniacal liquor blender |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE1003015A6 (en) * | 1989-03-20 | 1991-10-22 | Recticel | Nozzle for spray gun for forming a layer polyurethane on a surface. |
ATE375212T1 (en) * | 2003-06-27 | 2007-10-15 | Recticel | METHOD FOR PRODUCING A MOLDED PART COMPRISING A SPRAYED POLYURETH LAYER |
US20050223986A1 (en) * | 2004-04-12 | 2005-10-13 | Choi Soo Y | Gas diffusion shower head design for large area plasma enhanced chemical vapor deposition |
JP2007090221A (en) * | 2005-09-28 | 2007-04-12 | Yutaka Electronics Industry Co Ltd | Spray nozzle and spray system |
CN107552258B (en) | 2016-07-01 | 2019-06-07 | 江苏鲁汶仪器有限公司 | Gas injection apparatus |
CN107470050B (en) * | 2017-09-30 | 2023-04-18 | 江西远达环保有限公司 | Spray gun with cooling effect for desulfurization and denitrification |
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DE465801C (en) * | 1928-09-26 | Siemens Schuckertwerke Akt Ges | Angular nozzle for sandblasting blower | |
GB1512113A (en) * | 1975-09-08 | 1978-05-24 | Root Lowell Mfg Co | Sprayer nozzle |
DE3225844A1 (en) * | 1982-07-09 | 1984-01-19 | Sprimag Spritzmaschinenbau-Gesellschaft Mbh, 7312 Kirchheim | Process and apparatus for applying layers of thermoplastic plastics or hot melt adhesives |
DE3423373A1 (en) * | 1983-08-29 | 1985-03-07 | Institut für Getreideverarbeitung im VEB Kombinat Nahrungsmittel und Kaffee, DDR 1505 Bergholz-Rehbrücke | Nozzle for atomising viscous fluids |
-
1987
- 1987-04-28 EP EP19870303754 patent/EP0244204A1/en not_active Withdrawn
- 1987-04-28 AU AU72124/87A patent/AU7212487A/en not_active Abandoned
- 1987-04-28 CN CN198787104313A patent/CN87104313A/en active Pending
- 1987-04-28 JP JP10340687A patent/JPS62269767A/en active Pending
Patent Citations (4)
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DE465801C (en) * | 1928-09-26 | Siemens Schuckertwerke Akt Ges | Angular nozzle for sandblasting blower | |
GB1512113A (en) * | 1975-09-08 | 1978-05-24 | Root Lowell Mfg Co | Sprayer nozzle |
DE3225844A1 (en) * | 1982-07-09 | 1984-01-19 | Sprimag Spritzmaschinenbau-Gesellschaft Mbh, 7312 Kirchheim | Process and apparatus for applying layers of thermoplastic plastics or hot melt adhesives |
DE3423373A1 (en) * | 1983-08-29 | 1985-03-07 | Institut für Getreideverarbeitung im VEB Kombinat Nahrungsmittel und Kaffee, DDR 1505 Bergholz-Rehbrücke | Nozzle for atomising viscous fluids |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GR890100298A (en) * | 1989-05-05 | 1991-10-10 | Vni Pi Aljuminievoi Magnievoi | Device for atomizing a liquid |
WO1991016991A1 (en) * | 1990-05-09 | 1991-11-14 | Resch D R | Precisely adjustable atomizer |
US5232164A (en) * | 1990-05-09 | 1993-08-03 | Resch D R | Precisely adjustable atomizer |
WO1992013643A1 (en) * | 1991-02-05 | 1992-08-20 | Gunter Voss | Device for coating a pressing chamber with a lubricant |
US5609908A (en) * | 1991-02-05 | 1997-03-11 | Voss; Gunter | Apparatus for coating a pressing chamber with a lubricant |
DE4407779A1 (en) * | 1994-03-09 | 1995-09-14 | Total Feuerschutz Gmbh | Spray nozzle for generating spray mists |
DE4407779C2 (en) * | 1994-03-09 | 1997-07-31 | Total Feuerschutz Gmbh | Spray nozzle for generating spray mists |
EP0914871A3 (en) * | 1997-11-05 | 2000-05-10 | ITW Limited | Spray nozzle |
GB2392119A (en) * | 2002-07-13 | 2004-02-25 | Daryl Ind Ltd | A nozzle for a showerhead |
GB2392119B (en) * | 2002-07-13 | 2005-10-19 | Daryl Ind Ltd | Nozzle For A Shower Head |
DE102005037773B3 (en) * | 2005-08-10 | 2007-01-18 | Voss, Gunter M. | Solvent film application process for surface mold involves applying hollow-cone gas flow, applying medium, and applying hollow-cone gas flow at different gas pressure |
FR2926230A1 (en) * | 2008-01-10 | 2009-07-17 | Air Liquide | APPARATUS AND METHOD FOR VARYING THE PROPERTIES OF A MULTIPHASIC JET. |
WO2009092949A1 (en) * | 2008-01-10 | 2009-07-30 | L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Apparatus and method for varying the properties of a multiple-phase jet |
RU2475311C2 (en) * | 2008-01-10 | 2013-02-20 | Л'Эр Ликид Сосьете Аноним Пур Л'Этюд Э Л'Эксплуатасьон Де Проседе Жорж Клод | Device and method for varying multiphase jet properties |
CN101909761B (en) * | 2008-01-10 | 2013-05-01 | 乔治洛德方法研究和开发液化空气有限公司 | Apparatus and method for varying the properties of a multiple-phase jet |
WO2011014949A1 (en) * | 2009-08-06 | 2011-02-10 | Unifiller Systems Inc. | A nozzle apparatus for dispersing droplets of flowable material |
ES2543037A1 (en) * | 2014-09-17 | 2015-08-13 | Grupo Técnico Rivi, S.L. | Industrial lubrication system distributed by oil mist (Machine-translation by Google Translate, not legally binding) |
WO2016042189A1 (en) * | 2014-09-17 | 2016-03-24 | Grupo Técnico Rivi,S.L. | Industrial lubrication system distributed via oil mist |
CN105214532A (en) * | 2015-10-28 | 2016-01-06 | 贵州电网有限责任公司电力科学研究院 | New-type boiler denitration ammoniacal liquor blender |
Also Published As
Publication number | Publication date |
---|---|
AU7212487A (en) | 1987-10-29 |
JPS62269767A (en) | 1987-11-24 |
CN87104313A (en) | 1988-07-20 |
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Effective date: 19881103 |
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Inventor name: SEWELL, PETER CLIVE |